I know some ppl call this the idle screw but, it's not.



This screw adjust the air/fuel mix a the trottle body. That's why this screw comes sealed from the factory with gray paint, so nobody should mess with it. So I did now the ECU is sending a code 45. What is the right way to adjust this screw back to its proper position? Do I need any special equipment to read air/fuel ratio? How many turns should it be open; right now is approx.1/2 turn open.

Thanks for the replies!

 

hmmmmm i have always thought it was the idle screw. i had it on my car, ITR head with manifold and TB, and was adjusting it. no code.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tweety R &raquo;</TD></TR><TR><TD CLASS="quote">
This screw adjust the air/fuel mix a the trottle body</TD></TR></TABLE>

There is no fuel at the TB, so it can only adjust the air going through. It IS the idle adjustment screw. If It was running fine before adjustment, try disconnecting your batter for a while to reset your ECU. My civic through a CEL after adjusting the idle, but was fine after I reset it. My integra didn't have any probs, though.

 

Ok, this is what I think. In OBDII's if you touch this adjustment it messes up the mix and the ECU throws a code. I looks and acts as an idle screw because in certain way adjust the idle but, by adjusting the amount of air at idle. So if you move to the left the rpm gradually go up, if you move it to the right, the idle gradually goes down.

 

correct.

If you turn it counterclockwise, it backs the screw out and lets more air through, which raises the idle.

OBDII is picky...reset your ECU and give us the result.

Oh...and how is that 'like' an idle adjustment screw?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bryan305 &raquo;</TD></TR><TR><TD CLASS="quote">

There is no fuel at the TB, so it can only adjust the air going through. </TD></TR></TABLE>You're right!!! What was i thinking?
Well, the thing is if you move this screw, you'll have a code 45 sooner or later.(Too rich or too lean code)

 

that's cuz your ecu hasn't learned to adjust the fuel for that amount of air.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bryan305 &raquo;</TD></TR><TR><TD CLASS="quote">
OBDII is picky...reset your ECU and give us the result.</TD></TR></TABLE>
I've done it many times after I adjust the screw and I think I'm gettin' closer to the right position coz it takes longer to the code to show up. Some time even couple of days. I'll continue messing with it until it disappear.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bryan305 &raquo;</TD></TR><TR><TD CLASS="quote">Oh...and how is that 'like' an idle adjustment screw? </TD></TR></TABLE>Well, to me an idle screw is a mechanical adjustment that interacts directly with the trottle plate.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bryan305 &raquo;</TD></TR><TR><TD CLASS="quote">that's cuz your ecu hasn't learned to adjust the fuel for that amount of air.</TD></TR></TABLE>Now I see it! So, I just have to reset and reset until it disappear?

 

how are you resetting?

 

How can adjusting the idle screw affect air/fuel? Doesn't it just affect the amount of air let in at idle?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by [VTEC &raquo;</TD></TR><TR><TD CLASS="quote">TL]How can adjusting the idle screw affect air/fuel? Doesn't it just affect the amount of air let in at idle?</TD></TR></TABLE>

If the ecu is putting out a certain amount of fuel at idle, then you open that screw to let in more air, the ecu doesn't instantly recalibrate itself to the new mixture. So your motor idles lean till the ecu cna adjust.

 

From the Honda/Acura Service Manual, the proper way of adjusting this screw is to trip the service connector so that the check engine light comes on, setting the ECU to service mode. Then you disconnect the IACV. From here on you can adjust the idle screw. I'm almost 100% positive thats the procedure you have to take to adjust the idle screw cuz i remember spending time trying to re-adjust my idle. My buddy has the service manual so if you would like comformation on the procedure i'll have it verified.

 

Thanks guys!

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bryan305 &raquo;</TD></TR><TR><TD CLASS="quote">how are you resetting?</TD></TR></TABLE>I disconnect the big 30A fuse for the ign. at the engine compartment for 5 min. PUt it back on and let the engine idle for about 5 to 10 min.

 

I'm not sure about what fuse to pull, but I *thought* you had to pull the ecu backup fuse. I just disconnect the battery for like 30 min just to make sure it's resetted.

 

i thought it was a 10amp fuse. on the top second from the left.